Method and system for vibration dampening

ABSTRACT

A method and system dampens vibrations associated with a device installed in a system by supporting the device with one or more support members having a rigid support portion and a dampening support portion made from an elastic material. In one embodiment, an information handling system fan assembly is made with two shot injection molding to form a support member with an integrated dampener that holds a fan mount disposed in a cooling air channel defined by a fan housing. The fan housing, mount and rigid portion of the support member are formed with one shot from a substantially rigid material and the dampening portion is formed with another shot from a substantially elastic material. A fan couples to the fan mount for installation in the information handling system.

This application is a divisional of application No. 10/152,594, filedMay 21, 2002, now U.S. Pat. No. 6,912,127 issued on Jun. 28, 2005entitled “Method and System for Vibration Dampening” and naming DavidFrederick Hutchinson and Ahmed Mohiuddin as inventors, which is herebyincorporated by reference in its entirety

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates in general to the field of dampeningvibrations, and more particularly to a method and system for informationhandling system cooling fan vibration dampening.

2. Description of the Related Art

As the value and use of information continues to increase, individualsand businesses seek additional ways to process and store information.One option available to users is information handling systems. Aninformation handling system generally processes, compiles, stores,and/or communicates information or data for business, personal, or otherpurposes thereby allowing users to take advantage of the value of theinformation. Because technology and information handling needs andrequirements vary between different users or applications, informationhandling systems may also vary regarding what information is handled,how the information is handled, how much information is processed,stored, or communicated, and how quickly and efficiently the informationmay be processed, stored, or communicated. The variations in informationhandling systems allow for information handling systems to be general orconfigured for a specific user or specific use such as financialtransaction processing, airline reservations, enterprise data storage,or global communications. In addition, information handling systems mayinclude a variety of hardware and software components that may beconfigured to process, store, and communicate information and mayinclude one or more computer systems, data storage systems, andnetworking systems.

Information handling systems having played an important role inimproving worker and individual productivity by automating tasks andperforming complex computations. For instance, information handlingsystems commonly perform day-to-day operations in banks, libraries,research facilities, homes and other locations where workers andindividuals spend significant amounts of time in quiet thought toaccomplish complex tasks. Information handling systems assist by quietlytracking financial transactions and inventory, by acting as wordprocessors that record research results or by connecting to networks totransfer valuable information on a timely basis. Under a number ofcircumstances in which information handling systems operate, quietoperation is an important consideration for users.

One difficulty with keeping information handling system operations asquiet as possible is that the electronic components that perform orsupport information handling tend to generate heat that typically mustbe removed by cooling fans in order to ensure proper operation. Coolingfans often represent the greatest noise producing component of aninformation handling system. As information handling systems have grownmore powerful with greater power consumption and faster operatingspeeds, the need for cooling has increased, leading to the use of morepowerful cooling fans that operate at higher speeds and for greater timeperiods. To reduce the vibration and related noise of cooling fans,cooling fans are typically installed into information handling systemswith vibration dampers, such as elastic washers or grommets that absorbvibrations, such as rubber inserts. However, these vibration dampeningpieces increase the complexity of manufacturing information handlingsystems since they are often small pieces that are manually installedwith cooling fans.

SUMMARY OF THE INVENTION

Therefore a need has arisen for a method and system which dampensvibrations of system components to decrease system noise.

A further need exists for a method and system which incorporatesvibration dampening for a system component without substantiallyincreasing the complexity of assembling the component in the system.

In accordance with the present invention, a method and system areprovided which substantially reduces the disadvantages and problemsassociated with previous methods and systems for dampening vibrationnoise of a system component. Two shot injection molding of the componentsupport integrates rigid and dampening portions that install thecomponent in the system with vibration dampening.

More specifically, an information handling system cooling fan assemblyis molded as a single piece that includes a dampening portion to dampenvibrations generated through cooling fan operation. The cooling fanhousing defines a cooling air channel for the cooling fan to passcooling air through in order to cool heat-generating components of theinformation handling system. A cooling fan mount is disposed in thecooling air channel to support the cooling fan. Cooling fan mountsupports couple to the housing and the cooling fan mount to hold thecooling fan mount in the cooling air channel. The cooling fan mountsupport has a rigid portion formed by a substantially rigid material anda dampening portion formed by a vibration-absorbing material, such as anelastomer. A cooling fan couples to the cooling fan mount and thehousing couples to an information handling system to align cooling airflow to remove heat from heat-generating components.

In one embodiment, the cooling fan housing, mount and mount supports areformed as a single, integrated piece with a two shot plastic injection.A substantially rigid plastic is injected in one shot to form thecooling fan housing, mount and rigid portion of the mount supports. Anelastic plastic is injected in another shot to form the dampeningportion of the cooling fan mount support. For instance, the elasticmaterial is injected into a gap left during formation of the cooling fanmount support. The two shot injection molding process produces a singlefan assembly piece with the vibration-absorbing elastic portion of themount support integrated with the rigid portion. Thus, assembly of theinformation handling system involves coupling the fan to the mountsupport and the housing to the information handling system withoutseparate vibration absorbing grommets or pieces.

The present invention provides a number of important technicaladvantages. One example of an important technical advantage is thatvibration dampening provided for a component decreases the noiseassociated with operation of the component. For instance, a cooling fanoperates in an information handling system with vibrations isolated byan elastomer vibration dampening portion of the cooling fan support,while a rigid portion holds the fan securely in position. Theinformation handling system operates quietly, providing an environmentmore conducive to concentration by information handling system users.

Another example of an important technical advantage of the presentinvention is that information handling system assembly is simplified.For instance, the use of two shot plastic injection to form a singleintegrated piece having a rigid portion and an elastic portion providesreduced assembly steps for installing a fan assembly into an informationhandling system. The integrated vibration dampening section eliminatesor reduces the need for assembling additional vibration absorbinggrommets or other devices, thus reducing manual labor used duringinformation handling system assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may be better understood, and its numerousobjects, features and advantages made apparent to those skilled in theart by referencing the accompanying drawings. The use of the samereference number throughout the several figures designates a like orsimilar element.

FIG. 1 depicts a side view of a block diagram of an information handlingsystem;

FIG. 2 depicts a side cutaway view of a cooling fan mounted withsupports having integrated dampeners;

FIG. 3 depicts a top view of a cooling fan assembly with a cooling fanmount supported by dampener members;

FIG. 4 depicts assembly of a cooling fan to a cooling fan housing formedby two shot injection with rigid and elastic materials; and

FIG. 5 depicts a top view of a cooling fan mount coupled to a coolingfan housing with dampener support members.

DETAILED DESCRIPTION

Information handling systems are often used in noise-sensitiveenvironments so that quiet operation is an important designconsideration. The use of a cooling fan assembly with integratedvibration dampening aids in reducing the noise and vibration put out byan information handling system. For purposes of this application, aninformation handling system may include any instrumentality or aggregateof instrumentalities operable to compute, classify, process, transmit,receive, retrieve, originate, switch, store, display, manifest, detect,record, reproduce, handle, or utilize any form of information,intelligence, or data for business, scientific, control, or otherpurposes. For example, an information handling system may be a personalcomputer, a network storage device, or any other suitable device and mayvary in size, shape, performance, functionality, and price. Theinformation handling system may include random access memory (RAM), oneor more processing resources such as a central processing unit (CPU) orhardware or software control logic, ROM, and/or other types ofnonvolatile memory. Additional components of the information handlingsystem may include one or more disk drives, one or more network portsfor communicating with external devices as well as various input andoutput (I/O) devices, such as a keyboard, a mouse, and a video display.The information handling system may also include one or more busesoperable to transmit communications between the various hardwarecomponents.

Referring now to FIG. 1, a side cutaway view of an information handlingsystem 10 is depicted with a cooling air flow provided by a cooling fan14. Information handling system 10 includes electronic components thatgenerate heat. If heat-generating components are not cooled, such aswith a cooling air flow, failure of the heat-generating or other heatsensitive components may occur. One primary source of heat generation isa power supply 16, which typically accepts external AC power andtransforms the AC power into DC power of predetermined voltages for useby information handling system electronic components. Power supply 16provides power to cooling fan 14 through a power line 18. Anotherprimary heat generating component is a CPU 20 which performscomputations to support information handling functions. Typically, thefaster a CPU operates, the more heat it generates and the morespecialized and critical the transfer of heat from the CPU becomes.Thus, powerful CPUs generally depend on strong cooling air flow forproper operation. Other heat-generation components depicted ininformation handling system 10 include a hard drive 22 and memory 24. Inother embodiments, a variety of electronic components may be includedthat also generate heat, such as system control and graphics processors.

Referring now to FIG. 2, a side cutaway view of a cooling fan assemblyis depicted with integrated vibration dampening. A cooling fan housing26 defines a cooling air channel 28 through which cooling fan 14 drawsor pushes a cooling air flow. Power line 18 provides power to operatecooling fan 14 through a controller 30. Controller 30 varies cooling fanoperation to adjust the strength of the cooling air flow as needed tomaintain a predetermined temperature range within information handlingsystem 10. Cooling fan 14 and controller 30 are mounted to a cooling fanmount 32 with a pin 34. Cooling fan mount 32 is held disposed in coolingair channel 28 by support members 36 that have a generally rigid portion38 and an elastic dampener portion 40. Support member 36 couples tocooling fan mount 32 and cooling fan housing 26 to firmly support acooling fan 14 within cooling air channel 28. FIG. 3 depicts a top viewthat illustrates the opening provided for cooling air channel 28 toprovide a passage for cooling air flow between housing 26 and coolingfan mount 32. Support members 36 act as impeller struts that holdcooling fan mount 32 in place without substantially blocking the coolingair flow.

In one embodiment, support members 36 are integrated with cooling fanmount 32 and housing 26 as a single piece by forming the piece with twoshot plastic injection. One shot of the two shot plastic injection formscooling fan housing 26, cooling fan mount 32 and rigid portions 38 ofsupport member 36 with a substantially rigid plastic material. Anothershot of the two shot plastic injection forms dampener portions 40 ofsupport member 36 with an elastic material that absorbs vibrationsassociated with operation of cooling fan 14. The two shot plasticinjection integrates the rigid and elastic portions of support member 36into a single piece that both firmly couples cooling fan mount 32 tocooling fan housing 26 and absorbs vibrations from a cooling fan coupledto cooling fan mount 32. In alternative embodiments, additionaldampening portions may be included at various positions of the fanassembly to provide dampening as needed, such as at the point ofattachment of housing 26 to information handling system 10. An exampleof a plastic material for the formation of the rigid portions of supportmember 36 is glass filled polyester. For instance, rigid portion ofsupport member 36 is formed with 15% glass and housing 26 is formed with30% glass. Two examples of elastic materials are Polyone SynpreneIT37-031 and APA Alcryn 2060 BK. Alternative materials may be selectedto achieve desired strength and vibration dampening.

Referring now to FIG. 4, a blow-up side view of an assembly of a fan 14into a housing 26 illustrates the reduced complexity provided by anintegrated support member dampener 40. Fan 14 and controller 30 coupleto support mount 32 with pin 34 in essentially a single step. Coolingfan housing 26 is then installed by coupling an attachment point 42 toan information handling system housing. With vibration dampening forcooling fan 14 provided by dampening portion 40 of support members 36,the need to couple cooling fan housing 26 to information handling system10 with vibration dampening devices, such as elastic rubber grommets, issubstantially reduced or eliminated. If additional vibration dampeningneeds arise, the dampening material may be added at other points of thefan assembly, such as attachment point 42. Thus, the assembly processfor installing a fan 14 into an information handling system 10 involvesa reduced number of steps, reducing labor costs and part inventorymanagement needs.

In another embodiment depicted by FIG. 5, dampening portion 40 ofsupport member 36 is assembled as a separate piece. An attachment device42, such as a screw or a clip, secures dampening portion 40 to rigidportions 38 integrated with mount support 32 and housing 26. Althoughthe embodiment depicted by FIG. 5 involves additional steps to installwhen compared with the two shot injection integrated assembly, theinstallation of elastic portion 40 as a support member allowspreassembly of a cooling fan assembly complete with vibration dampeningbefore installation of the cooling fan assembly into an informationhandling system 10. Preassembly reduces the complexity of installationby allowing handling of the fan assembly as a separate unit beforeinstallation of vibration dampening, as opposed to dampening grommetsused with installation of fan housing 26, which requires more awkwardhandling of the information handling system.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

1. A method for manufacturing an information handling system cooling fanassembly, the method comprising: performing two shot injection moldingwith first and second plastic materials injected by first and secondshots wherein: the first shot inject molding with the first plasticforms a housing having a cooling channel, a fan mount operable to coupleto a cooling fan, and one or more fan mount supports to support the fanmount in the cooling channel, each fan mount support having a gap; andthe second shot injection molding with the second plastic forms adampening section in each gap of the fan mount supports to couple thefan mount to the housing.
 2. The method of claim 1 wherein the firstplastic comprises a substantially rigid plastic and the second plasticcomprises a substantially elastic plastic.
 3. The method of claim 1further comprising: coupling a cooling fan to the fan mount support todispose the cooling fan in the cooling channel.
 4. The method of claim 3further comprising: coupling the housing to an information handlingsystem to direct cooling air flow through the information handlingsystem to cool components of the information handling system.
 5. Themethod of claim 4 further comprising: powering the fan to flow airthrough the information handling system.
 6. The method of claim 1wherein the second shot injection molding is performed before the firstshot injection molding.